textproduct: Albany

WHAT HAS CHANGED

Updates to snowfall totals has resulted in Winter Storm Warnings to be issued for Schoharie, Schenectady, Albany, Rensselaer, Bennington and Windham Counties and Winter Weather Advisories for Montgomery, Fulton, northern Saratoga and southern Washington Counties. No other significant changes as a powerful nor'easter remains on track to affect the area later today through Monday.

KEY MESSAGES

1) A high impact Nor'Easter will bring heavy accumulating snowfall and strong winds to parts of the area late this afternoon through Monday, which will result in difficult to impossible travel conditions, near blizzard conditions in some areas, and possible downed trees and power lines.

2) Clipper-type low brings light accumulating snowfall potentially impacting the Wednesday morning commute.

3) Another storm system potentially brings light to moderate amounts of accumulating snow or a wintry mix Thu-Thu night with some uncertainty with the track and timing of the system.

DISCUSSION

KEY MESSAGE 1...

We remain on track for a powerful nor'easter to impact parts of the region later today through the day Monday. Latest guidance continues to show an upper level trough taking on a negative tilt as it nears the mid-Atlantic coast this afternoon and evening with strong divergent flow across the region. As a low pressure system nears the mid-Atlantic coast this afternoon, the strong divergent flow will lead to rapid intensification tonight lowering to near or slightly below 970 hPa by Monday morning (about a 35 to 40 hPa drop in 24 hours). The low looks to track very close to the 40N/70W benchmark Monday morning then continue its path northeastward into Monday night. This intensification will lead to an expanding precipitation shield which will extend northwestward into much of the region. Being on the cold side of this low, precipitation with this system will be all snow.

The rest of the overnight into today will feature some periods of light snow or flurries which could produce a light coating in spots by the afternoon hours. Snow associated with our nor'easter will begin to overspread the area from south to north late this afternoon into this evening continuing into the overnight hours. Mid- level FGEN present will support heavier snow bands extending into the region at times, especially from around the Capital District and points south and east, with the setup favoring pivoting bands (per CSTAR research). This area of greatest lift looks to intersect the dendritic growth zone (DGZ) at times which will support efficient snowfall rates (1 to 2 inches per hour). The period of heaviest snow looks to be tonight into early Monday morning before rates decrease through the day Monday as the storm begins to pull away.

There is high confidence for widespread double digit snowfall totals to occur for many areas south of Interstate 90. The highest amounts may actually occur across the Catskills as north to northeasterly flow will lead to upslope enhancement. In past winter storms, local ALY research favors this region seeing the greatest snowfall accumulations based on the north to northeasterly 925 hPa flow. Snowfall amounts have also increased slightly within the Capital District and into southern Vermont. A sharp snowfall gradient remains possible near or just north of Albany which may be on the northern edge of the heavier snow bands. There is where our confidence is lowest on overall totals. In addition, strong northeasterly flow aloft will support some downsloping effects downwind of the higher terrain in western New England which could bring lower totals into parts of Washington, Rensselaer and far western Bennington counties.

The updated snowfall amounts has led to the Winter Storm Warning to be expanded into the Capital District, Schoharie County and the rest of the eastern Catskills and into southern Vermont. Winter Weather Advisories have been issued for Montgomery, Fulton, northern Saratoga and southern Washington Counties which may be within the sharp snowfall gradient but could still pick up between 3 and 7 inches in some locations. The Adirondacks, Glens Falls/Lake George region and far western Mohawk Valley look to see the least snow from this event with generally 3 inches or less.

Wind will be the other impact with this event. A large wind field will be present with this system with gusts on the order of 35 to 45 mph favored, especially from the Capital District and points south and east with 25 to 35 mph wind gusts farther north and west. Wind gusts in Litchfield County could reach 50 mph in some locations. This will lead to areas of blowing snow with near blizzard conditions at times, especially for areas south and east of Albany. Travel in these areas will be very difficult to impossible, especially tonight into early Monday morning. the combination of heavy snow and strong winds can also lead to downed trees and power lines leading to some power outages.

KEY MESSAGE 2...

An active weather pattern continues on Tues after arctic high pressure briefly builds in from southeast Ontario and south/southwest Quebec during the day. High temps on Tue based on the NBM will be about 10-15 degrees below normal for late Feb with highs in the teens to lower 20s over the mtns and generally lower to mid 20s in the valleys with a few upper 20s over the mid Hudson Valley. The colder air mass will set the stage for the warm front ahead of a clipper low to bring accumulating snow Tue night/Wed morning. The low to mid level warm advection increases for a period of snow, as high chance to likely PoPs increase across the forecast area late Tue night into Wednesday morning. The NBM 24-hr probabilities of >1" of snowfall for the period ending 7 pm Wed across eastern NY and western New England are mainly 30-80%. The NBM 24-hr probabilities for the same timeframe for >3" of snow are 35-60% over the eastern Catskills, west/southwest Adirondacks and portions of western New England. A 1-3" snowfall across the forecast area is possible, as the front and wave moves through the region. Some impacts on the Wed morning commute will be possible with the cold surfaces and the potential for snow- covered roads with lows starting out in the single digits and lower teens before temps rise into the mid 20s to mid/upper 30s Wed pm.

KEY MESSAGE 3...

The active wave train continues, as a southern stream system may impact the region Thu-Thu night. The placement and track of the system varies on the EC/GFS AI, ensembles, medium range guidance and NBM. We stayed closed to the NBM here, which still favors a colder solution with snow with perhaps a brief mix to snow/rain in the Hudson River Valley. If the wave tracks from the Ohio Valley across PA and along or south of NYC and Long Island, then this system could bring another moderate to locally heavy snowfall to portions of the region. If the wave tracks further northward over upstate NY into western New England, then a transition to a wintry mix or rain may occur especially from the I- 90 corridor south. The latest forecast supports high chance and likely PoPs (50-70% range) for Thu pm into Thu night. Some impacts on the evening or morning commutes may occur with snow covered roads. We will continue to monitor the track, evolution, pcpn types and amounts with this system over the next several days to further assess potential impacts.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Through 12Z Monday...MVFR cigs open the TAF cycle at KGFL/KALB/KPSF with cigs 1.0-2.5 kft AGL with light snow and some patchy freezing drizzle with an upper level disturbance. Conditions are IFR conditions are occurring at KPOU with cigs just below 1 kft AGL. The conditions should remain widespread MVFR with cigs and possibly vsbys/cigs continuing IFR at KPOU between 12Z-16Z/Sun with the light snow. Widespread MVFR cigs with some light snow showers continue until the late morning for all the TAF sites until a brief lull occurs in the late morning through the early to mid pm, as cigs will rise to VFR levels north of KALB, but may linger at high MVFR levels at KALB/KPSF. KPOU will remain MVFR until the late am/early pm, but then the cigs/vsbys will rapidly lower to IFR/LIFR levels by 22Z/Sun in the stratiform snow shield to the powerful coastal Nor'easter. Conditions will lower to MVFR/IFR levels further north and east between 02Z-06Z/Mon for KALB/KPSF with snow moving in. PROB30 groups were used to bring the snow for KGFL between 05Z-08Z/Mon. Expect widespread IFR/LIFR conditions with SN/+SN to impact KPSF/KPOU after 06Z/Mon.

Winds will be light and variable in direction this morning at 4 KT or less. They will increase from the east to northeast at 5-10 KT in the late morning through the afternoon. Strong north to northeast winds increase to 10-18 KT tonight with some gusts 20-30 KT at KPOU/KPSF. We did include some LLWS groups in for KPOU/KPSF especially after 00Z-06Z/Mon, as the 2 kft AGL winds increase to 35-50 KT from the north/northeast. The LLWS was expanded northward after 06Z/Tue to KALB/KGFL.

Outlook...

Monday Night: Low Operational Impact. Breezy. NO SIG WX. Tuesday: Low Operational Impact. Breezy. NO SIG WX. Tuesday Night: Moderate Operational Impact. Chance of SN. Wednesday: High Operational Impact. Definite SN. Wednesday Night: Moderate Operational Impact. Chance of SHRA...SHSN. Thursday: Moderate Operational Impact. Chance of SN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...Winter Storm Warning from 1 PM this afternoon to 7 PM EST Monday for CTZ001-013. NY...Winter Storm Warning from 1 PM this afternoon to 7 PM EST Monday for NYZ058>061-063>066. Winter Weather Advisory from 10 PM this evening to 7 PM EST Monday for NYZ039>041-050-082-084. Winter Storm Warning from 7 PM this evening to 7 PM EST Monday for NYZ047>049-051>054. MA...Winter Storm Warning from 1 PM this afternoon to 7 PM EST Monday for MAZ001-025. VT...Winter Storm Warning from 7 PM this evening to 7 PM EST Monday for VTZ013>015.